Generally, it has been known that the global warming is influenced by the carbon dioxide caused by the combustion of petroleum oil fuel used in an internal-combustion engine.
In the current economic situation, exchanging or improving various pieces of equipment such as a vehicle, a heavy machine, or a boiler is difficult but the reduction of carbon dioxide has been strongly required.
In a machine such as an internal-combustion engine or a driving system, lubrication oil is used in order to reduce the friction caused during the operation of a gear or a piston. When lubrication oil is used in an internal-combustion engine or a driving system, the friction can be reduced to provide a smooth rotation of a gear or a piston for example, thus reducing the consumption amount of fuel (e.g., light oil, gasoline) and the emission amounts of carbon dioxide and other exhaust gas components caused in the combustion.
On the other hand, lubrication oil is oxidized and deteriorated when subjected to the use for a long period of time. The oxidized lubrication oil causes acid substance, varnish, or sludge for example, thus promoting deterioration such as an increased acid number or an increased viscosity. There are various disadvantages where such an acid substance for example causes the worn parts of an internal-combustion engine or the wear or lubrication oil having an increased viscosity causes an increased power loss, which hinders the operation of the internal-combustion engine.
The mechanical parts of the internal-combustion engine rust due to various causing factors such as water ingression by rain and wind for example. The rust causes an increased power loss, thus hindering the operation of the internal-combustion engine.
By the way, lubrication oil is added with (a) copolymer having a number average molecular weight in the range higher than 6300 and lower than 1200 of octadecene 1 and maleic anhydride and (b) dispersant/VI improver additive agent including a succinimide reaction product prepared from polyamine and acyclic hydrocarbyl-substituted succinic acylating agents. As a result, resolving agent disperses the varnish and sludge components in the entire oil to thereby prevent the accumulation thereof, according to the disclosed invention (see Patent Publication 1 for example).
Regarding petroleum oil fuel itself, it has been previously suggested to add, in a diesel engine, fuel additive substance to the petroleum oil fuel to provide a favorable combustion efficiency to thereby improve the fuel consumption (see Patent Publication 2 for example).